Runny nose, fishy smell?

Hi! I have an original flock of 4 month olds and recently added 2 americanas that are supposed to be around a year (my bf choice, not mine-he wanted eggs asap, I wanted to raise them) and have had them for about a month now. I have noticed that one of the new americanas always has a runny nose (both nostrils) and has a gross fishy smell to her face when I hold her. I also noticed once her nose was bubbling a few days ago. The other one who came with her has a slightly runny nose but only occasionally. They do not seem lethargic nor do their eyes seem puffy nor do I notice them sneezing. I called the feed store and they told me to give Duramycin for 7 days in their water. Question being- do I treat the others that do not show symptoms? Also, they told me that the chickens had colds....I have read elsewhere that chickens do not get colds....I am new to the chicken world and def do not know anything about their diseases yet except what I have glanced thru her on the site. Thanks so much.

Sounds like they have Coryza, a nasty virus chickens sometimes get. I'd treat all four with VetRx, which you can get at your feedstore most likely. In the future, when you bring home strange birds, always quarantine them away from your existing flock so you can watch for diseases or odd symptoms.
The signs of Coryza via google:

Facial swelling.

Purulent ocular and nasal discharge.

Swollen wattles.

Sneezing.

Dyspnoea.

Loss in condition.

Drop in egg production of 10-40%.

Inappetance

I'll check to see if I can find the link to the thread I posted when my birds were infected.

Huh, guess it was deleted? From what I remember, someone told me my birds would be carriers for life and I should cull them all and disinfect the coop. I just treated them with VetRx, and that was several years ago. New birds have come on the property without any problems. Just be careful next time you introduce new stock.

Oh darn.....thank you for looking though. I appreciate it. It seems that they either have a respitory infection or coryza (because of the stinky face) but from what I have read you should treat respitory infections with duramycin and the coryza with sulfa. Wondering if I can give them both just to be sure or if that would kill them? Also my feed store does not carry VetRx?

The best drug for coryza is sulfadimethoxine (Di-Methox, Albon, or Sulfamed-G) which you may have to order online. Click here of these 2 links, one for diseases to read about coryza and a site that sells DiMethox: http://edis.ifas.ufl.edu/ps044